Cumulonimbus clouds – Page 8

Dial “O” for rain; Odile that is

Unless the younger folks watch Turner Classic Movies or something like that, they will be clueless about what ther the reference to “dialing” is in the title. Oh, well. Heck, who even remembers what a Walkman was these days?

The heavy cloud shield of TS Odile is moving in with some light, spotty rain hereabouts right now. It will be interesting to see if today’s rain amounts to anything. Seems it could be a very Seattle-like rain day with those heavy layer clouds over us (Nimbostratus/Altostratus) and intermittent very light rain all day. Boring! (Is “boring” with an exclamation mark an oxymoron of sorts?)

NWS is excited about Odile, as any meteorologist not having snow in his veins would be, and have posted some daily rainfall records for this week. Of course, we’ve already set some rainfall records for September; can it happen again? They seem to be concerned about that possibility. Many of those September records, as many of you will remember I am sure, were associated with tropical storm Norma that busted into Arizona in early September 1970 as you will see¹. Workman Creek got 11 inches in one day back then. You can read about Norma’s doings here and whether the NWS forecasts were adequate.

The meteorological situation was very different with Norma, and that may be why we precipophiliacs could be “disappointed” by rain amounts with Odile–Norma had help from the configuration aloft; Odile not so much. However, in the days following Odile’s passage, that upper level trigger does fall into place over southern Cal, and we’ll have to watch out for some big thunderstorms in the couple of days AFTER Odile goes by when that upper level trigger (trough) still has some tropical air to work with. So, some really “interesting” weather ahead, the kind of weather we’ve forgotten can happen here in the many droughty years we’ve had lately.

Here, just hoping for some nice steady rains, not just sprinkles, that add up to something significant like a half an inch or more, keeping the desert green that bit longer, and maybe, some good scattered thunderstorms for a few days after the big cloud shield of Mr. Odile fades away. That will pretty much do it for our summer rain season I’m afraid.

Now, since we don’t like to do work that can be done better by others, these ones and this one, for example, so on to yesterday’s pretty cloud pictures. (Can’t get over the thought I might be disappointed in Odile’s rain here, expectations not real high, so don’t want to express them and make you a little sad; keeping a lid on thoughts of a big Odile rain for Catalina, don’t want to get too manic, etc.) Will just lay back and enjoy it…whatever comes.

Yesterday’s clouds²

10:00 AM. Cumulus development looked promising in the mid-day hours, but none over the Cat Mountains produced ice. Was surprised that didn't happen. — 10:00 AM. Cumulus development looked promising in the mid-day hours, but none over the Cat Mountains produced ice. Was surprised that didn’t happen. Note glistening rocks dur to the recent rains.

: 11:59 AM. Towering Cumulus and Cumulonimbus clouds begin lining the International border. Warning: adult commentary included in photo, the kind you see every day on TEEVEE.

1:18 PM. High cloud shield from Odile’s advance creeps over Tucson from the south. Cumulonimbus clouds can be seen in the extreme distance.

4:06 PM. Cirrus and Altostratus have overspread the sky, and the darkening to the S-SW looks ominous in view of Odile’s approach after wrecking southern Baja.

Followed by a great sunset, one deserving of more than one example. No details, just enjoy.

The End

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¹The present Arthur was in Durango starting his first job as a weather forecaster for the great Colorado River Basin Pilot Project, a randomized cloud seeding experiment, when Norma’s remains hit and flooded the Animas River there. I was inside a vaudeville theater listening to the rain pound on the roof, the audience of that melodrama, too, distracted a time or two, and also being distracted by Durango school teacher, Janet James, whom I had taking a liking to. She was there that night, too, but not with me. Wonder what happened to her?

²Caution: one photo is annotated with adult humor.

Summer thunderama returns to Catalina for a day

Against the deepening blue skies over us as the sun continues its descent to overhead of the Equator, coming right up (September 22nd, AZ time), our late summer Cumulus and thunderheads become even more spectacular. You can see the whole cloud day here, courtesy of the University of Arizona, if you would like to avoid the tedium of examining photos and captions by yours truly.

I got very excited about a small thunderstorm that took shape almost overhead of Sutherland Heights, and you know what that means. Yes, too many photos of almost the same thing! See below. Captured it, too, BEFORE it even started to rain, or even thought about it. Produced a large number of cloud-to-ground strikes in the vicinity, too, more that you would expect from such a small storm. Also, if you could see them, you saw repeated split strikes, ones in the core of the rain, and at the same time a branch in clear air to the north, a mile or two quite a ways from the rain shaft. I had not seen that before happen over and over again. Samaniego Peak reported the only rain, 0.28 inches, in the ALERT Catalina Mountain gauges, like twice that in the core of the shaft.

Then, of course, we had a lot of LTG in the early evening and nighttime hours to the NE-S-SW as storms marched across Tucson, Marana and Oro Valley. Missed us, though. A place in Avra Valley got an inch.

That’s pretty much it for your cloud and weather day yesterday. Farther below, the details….

Mods see nothing for a couple of days, until Monday, when the moisture from now Hurricane Odile begins to work its way into AZ.

Yesterday’s clouds

10:30 AM. After a completely clear morning, Cu began to pop up around 9:30 AM. This size by 10:30 AM gave hope that the day would have full Cumulonimbus clouds later on.

DSC_0016-1 — 3:26 PM. Just a pretty scene. Note the contrast between the blue sky and the white glaciated top of this Cumulonimbus calvus. Note too, that there is only a faint rain shaft underneath (behind ridge top, that smoother area).

DSC_0022-1 — 3:48 PM. Here’s where you and me saw a lot of rain promise in this developing cloud base on our nearby mountains. Almost every cloud that had this much base or a bit more, eventually rained. Maybe it would explode into something really big with powerful winds! Well, “really big” didn’t happen, but it did do its job with nice, but small rain shaft a little later.

DSC_0036-1 — 4:01 PM. Excitement builds as base grows a little wider; rain excitement is now guaranteed. I can only imagine what you were thinking when you saw this, and how happy you were since it could lead to a nice rain on you. LTG and wind, just ahead.

Ann DSC_0038-2 — 4:05 PM. Bottom beginning to drop out now!

DSC_0039-2 — 4:06 PM. Graupel and/or large drop strand (center) just began to appear (look hard). This was taken just after the first cloud-to-ground strike near Samaniego Peak (center).

DSC_0045-1 — 4:11 PM. The gush reaches the ground amid frequent split cloud-to-ground LTG strikes, ones near or in the core, and repeated strikes a mile or two to the right in clear air.

4:17 PM. Our little rain shaft offered up a lot of wind, probably in the neighborhood of 50 mph, judging by the spread of the rain “plume” on the ground to the right. Some drops and gusty winds of 20-30 mph reached Sutherland Heights soon after this, making for an especially pleasant evening outside.

DSC_0089-2 — 5:42 PM. An isolated thunderstorm, rumbling to the west of the Tortolitas yesterday evening , offered up this dramatic shadow scene.Its remnant providing a sunset highlight.

DSC_0114-1 — 6:37 PM. The remains of the thunderstorm shown in the photo above provided a nice sunset highlight as they so often do.

Special low cloud base day ahead; yesterday’s pretty cloud scenes

Today will be a special one in the desert. Cumulus bases are going to be really LOW for summer, maybe only 3-4 kft above the ground, and likely warmer than 15 C (50 F). Maybe 50 F doesn’t sound special, but it is. A base temperature of summer clouds that warm is rarely observed here. And with that, and all the posts here about the temperatures that ice forms (around -10 C, 14 F) are out the window. Ice will form at much higher temperatures than usual.

This is because on a day when the Cumulus bases are that warm, rain forms by collisions between droplets before clouds even reach the -5 C (23 F) level, the highest temperature at which Ma Nature can produce ice. Rain mgiht even form in our clouds today even before the freezing level itself!

This is so exciting for an Arizonan who has studied ice-in-clouds development over the years because today ice will form in clouds around the -5 to -10 C level, and the mechanism of Mssrs Hallett and Mossop will be heavily involved as well as other lesser understood mechanisms to form ice in clouds today. And, along with that high ice-forming temperature will be categories of ice crystals that are rarely seen here, needles and hollow sheaths, ones that form at temperatures in clouds warmer than -10 C! You can see how excited Mr. Cloud Maven Person is. For comparison, it would be like a bird watcher seeing a _________, something pretty rare go by.

Dewpoint temperatures are running in the upper 60s and was 70 F (!) at TUS earlier this morning! Indicative of a really, really moist day from a cloud standpoint even now is that line of Stratus fractus cloud halfway down on Samaniego (Sam) Ridge. And this is BEFORE rain has fallen. Not too unusual to see something like that AFTER a good rain, but before, its pretty rare.

All in all, a very tropical day ahead, very “Floridian” I would call it, and that means more water in the clouds above us ready to fall out, and more “fuel” to send those warm plumes of Cumulus turrets spaceward. That’s because heat is released to the air around cloud droplets as then form, and the more “condensate” the more heat. The warmer the cloud bases, the more condensate that occurs. Its quite a feedback loop.

The last time we had bases this warm and low, some “lucky” areas got “Floridian” dumps of rain, that is, 3 inches in an hour. (Three inches in an hour is pretty common in Florida in the summer.)

However, need some heating and/or a good symoptic situation to gather up the clouds today if we are to get more than just high humidity from Norbert’s remains. Last night’s model run from the U of AZ was not real supportive of a great day because while the humidity is here, and upper level situation is going in the wrong direction, is not going to help much. A lot of what we needed was expended over night in huge storms that are raking central and northern AZ now, with some sites in PHX reporting up to 2 inches since midnight! And as that upper air configuration responsible for their great rains moves away, what’s right behind it up there, will try to squash clouds.

So, while we have the ingredients down low for an exceptional rain day, its not in the bag. What’s worse is that drier air is now foretold to roll in from the west by tomorrow, further diminishing (not eliminating, though) the chances for a decent rain here in Catalina. “Egad”, considering all the promise that “Norbert” once held for us!

So, in sum, a bit clueless here as to what exactly kind of day we’re going to have. “Truth-in-packaging” portion of blog. I see rain has formed just now (6:41 AM) on Samaniego Ridge, AND to the S-SW, very good sign!

—a note on air quality—as inferred from visibility in a humid situation——–

Another thing you will notice is how clean the air is. We have tremendous humidity, and unlike smog-filled air back east, the sky will be blue, and the visibility good. If you’ve ever been back East, you’ll know that in most areas the sky between the clouds on humid days is pretty white, and horizontal visibility is reduced in the moist air, say ahead of a cold-cool front in summer. This is due to large haze particles that have become droplets before water saturation has been reached, a phenomenon called deliquescence. Its horrible. Really ruins the sky back there on humid days.

Enough semi-technical blather. We’re mostly about pretty cloud pictures here.

Yesterday’s clouds

There were some spectacular scenes yesterday, even though it was disappointing as a rain day, only a late afternoon trace here in Sutherland Heights. Here are some of the best.

6:34 AM. Altocumulus lenticularis hovers over and a little downwind of the Catalinas.

10:03 AM. First Cumulus begin to form on the Catalinas, later than expected. I will using the words, “expected” and “unexpected” a lot today.

1:21 PM. First ice seen, lower left top of blue sky and cloud border. Can you see it?

DSC_0097-1 — 1:24 PM. Soon after the first ice is seen, out pops the rain, that very faint haze in the center of the photo.

2:12 PM. Mt Lemmon receiving 0.79 inches of rain in about an hour from this little guy. Note that the peak is TOTALLY obscured by this rain shaft.

12:24 PM. Cumulus clouds kind of muddled around up there when yours truly was expecting a sudden eruption at any time. Really did not happen yesterday.

DSC_00870-1 — 12:26 PM. Mostly just a pretty scene, the blue sky, the Altocumulus perlucidus, and the Cumulus congestus erectus.

DSC_0116-1 — 4:17 PM. It was especially gratifying, after kind of a non event day, to have this unexpected late eruption of a Cumulonimbus NW of Catalina. Meant chances weren’t quite over for nearby developments.

5:03 PM. Cumulus cloud street trails off the Catalinas. Will it do anything?

5:21 PM. The ragged edge of the higher layer leads to a series of crepescular rays in the falling rain, while the Cu congestus turret sends a long shadow Catalinaward, A gap in the clouds allows the sun to shine on the rain falling in Oro Valley then. Can you imagine how great the rainbow was on the other side, say from the Tortolita Mountains? The rainbow isn’t seen in the forward scattering direction because its due to reflected light back toward the sun from within the raindrops.

5:22 PM. Nice lighting on Samaniego Ridge, rainbow imminent,

5:24 PM. Magnificent, the lighting, the rainbow. How lucky we are to be here!

6:56 PM. Just when you thought the day was finished, this surprise. Well, it was to me, that’s for sure!

6:58 PM. Ghostly-like late blooming Cumulonimbus calvus and Cumulus congestus clouds rise up against the falling temperatures. Pretty neat sight.[/caption]

6:58 PM. More unexpected strong developments to the west after sunset.

The End!

Heck, if I worked on this much longer, the answer to what’s going to happen today would be in!

Rainy “mammoths” return; future remains cloudy

We saw some great shafts yesterday, and their content did not disappoint where they landed; 1.61 inches fell at a Saddlebrooke Ranch site, though only 0.06 inches in The Heights. Also, this piece contains a footnote.

: 8:15 AM. The usual summer Altocumulus perlucidus deck.

10:56 AM. Cumulus begin to form under a layer of Altostratus translucidus. Now some people would call that higher layer “Cirrus”, but remember that in our cloud definitions, only one variety of Cirrus can have gray shading in the middle of the day, and that’s Cirrus spissatus, which besides is in much smaller patches that this. I know its crazy, but there it is.

2:19 PM. Some darkening of the sky to the S--SSW toward Tucson. Best if you don't look at radar to see if there's anything there if you want to enhance your cloud interpreting skill set. Just let it come, if it is. — 2:19 PM. Some darkening of the sky to the S–SSW toward Tucson. Its best if you don’t look at radar to see if there’s anything down there if you want to enhance your cloud interpreting skill set. Just let it come, if it is. Maybe its a spiral band around H. Norbert! (There was a big line of echoes heading this way….) Not much was going on over the Catalinas.

3:01 PM. Earllier darkening not disappointing! She'll be comin' round the mountain when she comes"! — 3:01 PM. Earlier darkening not disappointing! “She’ll be comin’ ’round the mountain when she comes”! What a great and dramatic scene this was.

3:28 PM. Things are happening fast as the rain shafts from this system tumble down Samaniego/Pusch Ridge! — 3:28 PM. Things are happening fast as the rain shafts from this system tumble down Samaniego/Pusch Ridges! Winds in those shafts likely exceeded 50 mph where you see them racing down those slopes, Nice, promising base forming on this side of the mountains, too.

3:56 PM. Stupendous shafts slide along Sam Ridge, while gusty SE winds blow in the Heights, pushing clouds up over and to the north of us.

4:05 PM. One of the new cloud bases cut loose, but just to the NE of Sutherland Heights. Oh, me, so close.

6:43 PM. Day clouds with an OK sunset on the several layers of debris clouds leftover from those great storms.

The weather ahead….

Just glimpsing the mighty U of AZ mod seems to suggest that there are two more days with substantial rains in the area ahead. Great! So, more great clouds and shafts to shoot, to be a little alliterative there at the end. Charge camera battery. Check weather service and what Bob has to say as well. Haven’t got time to make a good forecast…. hahaha, sort of.

The weather WAY ahead

In the long range, I found this important plot from last night interesting, and I know I speak for you as well:

A true "spaghetti" plot from NOAA factory based on last evening's global data. Its valid for Sunday, at 5 PM AST, September 21st. — A true “spaghetti” plot from the NOAA factory based on last evening’s global data. Its valid for Sunday, at 5 PM AST, September 21st.

Now it does appear from this plot that there is a ridge in the future along the West Coast, manifested¹ (what a great word) by that hump in all those multicolored lines along the West Coast), a trough in the East (MANIFESTED by the dip in those same lines east of the Rockies). That means that the summer rain season, might actually be extended some instead of ending completely with the current rejuvenation. The summer moisture can extrude farther to the north when a ridge is present in the West. In the daily forecast maps, showers do return to this area after the present tropical regime ends, and that scenario is that bit reinforced by what “spaghetti” says.

The End

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¹To sound more erudite, you might use that word today when discussing the outcomes of yesterday’s NCAA college football games with your sports friends. An example: “The Washington Huskies defense is not as good as we had hoped it would be as MANIFESTED by the FIFTY-TWO points in gave up to the Eastern Washington Eagles, a lower division team.”

3:56 PM. A little dessert, another shaft for you, a real good one over there on the Gap.

More like it; 0.43 inches in The Heights, 3.07 inches on Ms. Mt. Lemmon!

Thank you, second burst of rain after about 8:15 PM. And what a great total on The Lemmon! Fantastic, unless some roads were washed out. 1.93 inches fell in only an hour up there. 1.85 inches fell in an hour at White Tail over there by the highway.

Below, cribbed from the Pima County ALERT gauge line up, these 24 h totals, ending at 4 AM AST:

Catalina Area
    1010     0.00       0.00       0.00        0.00         0.28      Golder Ranch                 Horseshoe Bend Rd in Saddlebrooke
    1020     0.00       0.00       0.00        0.00         0.28      Oracle Ranger Stati          approximately 0.5 mi SW of Oracle
    1040     0.00       0.00       0.00        0.00         0.43      Dodge Tank                   Edwin Rd 1.3 mi E of Lago Del Oro Parkway
    1050     0.00       0.00       0.00        0.00         0.43      Cherry Spring                approximately 1.5 mi W of Charouleau Gap
    1060     0.00       0.00       0.00        0.00         0.55      Pig Spring                   approximately 1.1 mi NE of Charouleau Gap
    1070     0.00       0.00       0.00        0.04         0.87      Cargodera Canyon             NE corner of Catalina State Park
    1080     0.00       0.00       0.00        0.00         0.24      CDO @ Rancho Solano          Cañada Del Oro Wash NE of Saddlebrooke
    1100     0.00       0.00       0.00        0.00         0.51      CDO @ Golder Rd              Cañada Del Oro Wash at Golder Ranch Rd

Santa Catalina Mountains
    1030     0.00       0.00       0.00        0.00         0.75      Oracle Ridge                 Oracle Ridge, approximately 1.5 mi N of Rice Peak
    1090     0.00       0.00       0.00        0.04         3.07      Mt. Lemmon                   Mount Lemmon
    1110     0.00       0.00       0.00        0.00         0.63      CDO @ Coronado Camp          Cañada Del Oro Wash 0.3 mi S of Coronado Camp
    1130     0.00       0.00       0.00        0.00         1.69      Samaniego Peak               Samaniego Peak on Samaniego Ridge
    1140     0.00       0.00       0.00        0.00         0.94      Dan Saddle                   Dan Saddle on Oracle Ridge
    2150     0.00       0.00       0.00        0.04         2.72      White Tail                   Catalina Hwy 0.8 mi W of Palisade Ranger Station
    2280     0.00       0.00       0.00        0.00         0.59      Green Mountain               Green Mountain
    2290     0.00       0.00       0.00        0.00         1.18      Marshall Gulch               Sabino Creek 0.6 mi SSE of Marshall Gulch

Looks like scattered showers today; a typical sequence after something major happens, like last night, is for the atmosphere to compensate with some drier air. So, today should be GORGEOUS in Cumulus clouds that pile up here and there on the mountains, but don’t expect to get shafted unless you’re real lucky. Wider spread rains expected tomorrow….

Yesterday’s clouds, if you care

Of course, you can the whole day in a hurry here, courtesy of the U of Arizona Wildcats Weather Department, in case you’d like to avoid all the cloud blather below….

DSC_0239-1 — 6:20 AM. I/m calling this Altocumulus. Don’t see any ice falling out here, but some did off to the SW. Being an all water droplet cloud, I hope you were telling anyone that you were with, that, “Hell, this layer will burn off fast” since you know that water droplet clouds are more vulnerable to evaporating in sunlight than ice clouds like Altostratus, or Cirrus. And when this layer burns off fast, the Cumulus will arise in a hurry. Its great that you might have said that.

9:13 AM. That layer is mostly gone, and there come the Cu!

1:03 PM. The inevitable Cumulonimbus capillatus incus has arisen over there by Kitt Peak.
But this photo is special for you because if you look closely, as I know you will, there is also a big dust devil near the Tucson Mountains (center of photo). I’ve noticed a LOT of dust devils form in nearly that same spot where this one is. Must be exciting to live down there!

1:30 PM. Another daily benchmark, “First Ice” on the Catalinas. The ragged turret remains on the left have some ice underneath them if you look closely again, as I know you probably will. If you had an aircraft with cloud physics instrumentation and you were looking for the amount ice that formed in those ragged turrets, ones that once looked like the one in the center, nice and puffy, you would best fly toward the bottom of the rags, not at the top since as the droplets in the cloud shrink due to evaporation, the ice-forming stops. Thus sometimes the coldest part of the cloud in those rags has the fewest ice crystals, and more are found lower down, ones that formed by the freezing of those once larger drops, as would be starting to take place in the puffy parts.

3:56 PM. The rarely seen pileus cap which I seem to photograph everyday on a Catalina mountain Cumulus congestus cloud top. Very pretty, and SO DELICATE!
Things had kind of stagnated as far as Cumulus development went at this point over the Catalinas. Lots of small Cbs, but nothing really shot up, as it was beginning to do to the southwest and west.

4:15 PM. Another rarely seen pileus top on a Cumulus congestus converting into a Cumulonimbus calvus; ice in a fading, glaciated turret is visible on the left (that smooth portion). Still, these tops ain’t much in height.

5:57 PM. Now the big boys to the SW are approaching with huge “plumes” of Altostratus cumulonimbogenitus–you knew that, though in fading versions it appeared. Note dust plume on the right obscuring part of the Tortolita Mountains. And with their approach, and with the dust plume over there, you could easily figure that the wind was gonna blow pretty hard.

6:00 PM. Only four minutes later, the dust was moving in and the wind was blowing from the SW at 25 to 35 mph. When the wind starts up, look up! That wind will be pushing the air over you up, and often existing darken as their tops rise, or new clouds form. Here, and in the next shot, that SW wind is pushing the air up on the slopes of the Catalina Mountains. Was hoping to see the strands start to fall from these bases near us, maybe feel some “rain plops” as we call them, those giant drops first out the bottom, but that didn’t happen here, but over there on Ms. Lemmon and Samaniego Ridge after that. Oh, well.

6:06 PM. Another example of the clouds that piled up on the Catalinas as that SW wind was blowing. Wasn’t long after this that Ms. Lemmon was obscured in rain.

Unexpected ice; rain to fall in September

Like you, I did not expect to see ice-in-clouds yesterday. I could feel your surprise when I looked to the north and saw traces of it in the exhaling part of a Cumulus congestus–like you, really didn’t think I’d see clouds that large, either. But there the ice was.

Later, it was even more obvious, and a fat cell even developed up there toward Globe in mid-afternoon. Didn’t expect to see one so close.

Also, did you catch the cluster of Cumulonimbi on the north horizon at sunrise? That was an unexpected sight for you and me as well.

I wonder, too, if you were down at Steam Pump and Oracle you noticed that a few drops of rain fell? That was really unbelievable, since it was practically clear overhead when I exited the PF gym and saw them on the car I had just washed and waxed in the belief that no rain could fall for at least 10 days. Yes, it was a day of surprises for both of us.

Didn’t think I’d be bloggin’ today, either. Life has so many unexpected twists and turns.

Yesterday’s clouds

: 6:05 AM. Unexpected sighting number 1: Dawn Cumulonimbi up there toward the Mogollon Rim.

11:37 AM. Unexpected sighting number two, ice. See far right frizzy, smooth area in "exhaust" part of Cu. — 11:07 AM. Unexpected sighting number two, ice! See center right frizzy, smooth area in “exhaust” part of Cu.

11:37 AM. Unexpected sighting #3: Didn't think those turrets could extrude so far into the extremely dry air above those tops, but there it is, extruding like anything. (Center right). Also note the ice in the lower tops, left center, and the hint of a rain shaft! Unbelievable. — 11:37 AM. Unexpected sighting #3: Didn’t think those turrets could extrude so far into the extremely dry air above those tops, but there it is, extruding like anything. (Center right). Also note the ice in the lower tops, left center, and the hint of a rain shaft! Unbelievable. The dark blob at left in mid-air, obscuring a portion of the cloud, is a pipevine swallowtail butterfly that surprised me by flying into the frame as I snapped the photo. Yesterday may have been the most surprising day of my life, maybe yours, too.

2:18 PM. “USN4”: This gargantuan cell up there by Globe. Unbelievable that a cell this big was so close to our area considering all the dry air that was moving in.

2:28 PM. A surprisingly thin turret that has gone completely to ice (right side). The extruding turret on the left, certainly would have some ice in it, but also, as you can see from its texture, has a lot of liquid cloud droplets in it, too. This is a nice example of the glaciation cycle in a small cloud.

3:40 PM. Showers, and likely some thunder out there, just a few miles N of the Biosphere 2 facility. A pretty scene since the blue of the sky is darker now as the sun's elevation sinks toward the winter solstice. — 3:40 PM. Showers, and likely some thunder out there, just a few miles N of the Biosphere 2 facility. A pretty scene since the blue of the sky is darker now as the sun’s elevation sinks toward the winter solstice.

3:48 PM. Thunder beyond the Lemmon. The turret on the left has converted to all ice, while the mounding ones in the center and right, still have some liquid cloud droplets. The soft-serve look, compared to the crenellations of droplet clouds is due to the differences in concentrations. There are always few ice particle concentrations than droplet concentrations so droplet clouds look thicker, have sharper edges, more detail, but, we've been over this more than a few times. Sorry to belabor the point. — 3:48 PM. Thunder beyond the Lemmon. The turret on the left has converted to all ice, while the mounding one in the center, still has some liquid cloud droplets. The “soft-serve” look on the left, compared to the crenelations of droplet clouds, in particular, that darker turret in the center, is due to the differences in concentrations between the two phases. There are always fewer ice particle concentrations than droplet concentrations in clouds, and so droplet clouds look thicker, have sharper edges, more detail. But, we’ve been over this more than a few times. Sorry to belabor the point.

The weather way ahead

Mods continuing to show rain in our area sometime between the 6th and 12th of September, which would result in a non-rainless September. Sometimes, those mods think its due to a tropical storm remnant of a tropical storm that hasn’t formed yet. So, its quite mystical, that rain.
Still, the indications are that some rain will return after the long dry spell ahead.

Putting raingauge away now…

A measly 0.01 inches is all we got here yesterday in a Seattle-like rain from an overcast that sputtered drops drown over a couple of hours, one that could barely wet the pavement, if we had any here in Sutherland Heights. Of course, we surely drooled at the close call that drained Saddlebrooke yesterday afternoon (see below). Probably washed more golf balls into the CDO wash like that storm did last year…

Also, 0.75 inches fell, too, where Ina crosses the CDO wash yesterday, “so close, and yet so far away”, as the song says. Oh, well, another missed rain that I have to crybaby about¹. Will get some final pictures of the 2014 summer greening today before it fades away in the many dry days ahead to help make me feel better now that its over.

Here’s your cloud story for yesterday. It was pretty neat one, full of hope, even if that hope was eventually dissipated unless you lived in Saddlebrooke… The U of AZ time lapse film for yesterday is great, btw.

6:31 AM. I am going to say these are Altocumulus castellanus clouds, though they are a little low and large for that genera.

6:33 AM. This was a pretty scene... Here an isolated Ac cas rises up. Distant small Cumulonimbus clouds, weak ones, can be seen on the horizon. — 6:33 AM. This was a pretty scene… Here an isolated Ac cas rises up. Distant small Cumulonimbus clouds, weak ones, can be seen on the horizon.

9:18 AM. Before long, those pretty Cumulus clouds were springing to life off the Catalina Mountains, the sky so blue behind them.

9:19 AM. A rare "High Temperature Contrail" (HTC) slices through some very thin Altocumulus perlucidus. This aircraft phenomenon has also been called, "APIPs" for Aircraft Produced Ice Particles.) — 9:19 AM. A rare “High Temperature Contrail” (HTC) slices through some very thin Altocumulus perlucidus. This aircraft phenomenon has also been called, “APIPs” for Aircraft Produced Ice Particles.) Recall that Appleman (1953) said that an aircraft couldn’t produce a contrail at temperature above about -35 C. But, he was WRONG. They can do it in a water-saturated environment at much higher temperatures, even as high as -8 C (see Rangno and Hobbs 1983, *J. Clim. and Appl. Meteor*., available through the Amer. Meteor. Soc. for free, an open journal kind of thing.)

11:48 AM. Before noon, all thoughts of past glory was gone as the Big Boys arose in a hurry. What a dump here! The cloud, since it is not showing an anvil nor obvious fibrous appearance, would be a Cumulonimbus calvus — 11:48 AM. Before noon, all thoughts of past glory were gone as the Big Boys arose in a hurry. What a dump here! The cloud, since it is not showing an anvil nor obvious fibrous appearance, still pretty cauliflowery even though the discerning CMJ would not be fooled by its icy composition, it would be a Cumulonimbus calvus (“bald”).

3:40 PM. Probably THE most hopeful scene of the day. A large complex of Cumulonimbus clouds was emerging from the Tucson mountains, heading in this direction. But more importantly, were the cloud bases forming over Oro Valley ahead of it, likely, it seemed to be pushed upward by the outflowing winds ahead of the distant cells. Also, that cloud bases were forming and extending westward from the distant cells offered another rain-filled scenario that could happen as they approached from the SW.

4:14 PM. When the southwest wind arrived, it did in fact cause the clouds overhead to swell up like aphids on a Seattle rose bush, but as bad luck would have it, they were just to the north of us and over Saddlebrooke where they all all those amenities and don't really need a lot of rain. — 4:14 PM. When the southwest wind arrived, it did in fact cause the clouds overhead to swell up like aphids on a Seattle rose bush, but as bad luck would have it, they were piling up just to the north of us and over Saddlebrooke where they all all those amenities and don’t really need a lot of rain.

4:40 PM. After the first base dropped its load a little beyond Saddlebrooke, another cloud base darkened and expanded over Saddlebrooke, but this time, began to unload there. Here, like the seldom seen pileus cloud, these strands of the largest drops being to pour out of the collapsing updraft. You have about two minutes to see this happen because if you look away, the next time you look there will be nothing but the “black shaft.”

4:45 PM. A remarkable transformation. How can so much water be up there in a cloud? — 4:45 PM. A remarkable transformation. How can so much water, you wonder, be up there in a cloud?

6:05 PM. As the threat of any significant rain faded away, there was at least some "lighting" excitement, produced for just seconds as the sun shone on this....Stratus fractus cloud. — 6:05 PM. As the threat of any significant rain faded away, there was at least some “lighting” excitement, produced for just seconds as the sun shone on this….Stratus fractus cloud. Again, you must be watching at all times to catch these little highlights.

6:58 PM. Time to say goodbye to Cumulus and Cumulonimbus clouds like these, until maybe next summer.

The End. Probably will go on a hiatus now.

——————–

¹Its good to remember that there is a little crybaby in all of us, isn’t there?

Last chance for August rain#2

That would be today…. 🙁

First, this sight yesterday afternoon was interesting to me and I thought you should see it.

2:09 PM. Multi-strands of rain pour out of large cloud base. You won't see such tiny features like this very often. Usually represent very large drops, formerly hail or soft hail we call graupel. — 2:09 PM. Multi-strands of rain (aka, “dancing strands”) pour out of large, firm cloud base in Oro Valley. You won’t see such tiny features like this very often. Usually represent very large drops, formerly hail or soft hail we call graupel up higher. There are in this type of cloud always very tiny strands of graupel and hai aloft like this, but not so separated and so dense as here. The ones aloft might only be 10 yards (“meters”, if you’re thinking outside of football) wide. The rest of the rain shaft on the far right is in the fading mode, decreasing as the Cumulonimbus cloud above has exhausted its liquid water fuel (the part above the rain; its just rain, its “rained out”, no real cloud until much higher up when you get into the ice part, snowflakes.)

Second, it would appear that I hit the “publish” button before I intended to, before I really got going and figured out what I was going to say. I was no where near that button!

Third, this will be an assembly job, if anyone is out there, this piece will be gradually coming together, the nuerous errors being corrected on the fly, if it ever really does come together….

Maybe I will deflect attention with a spaghetti plot, get people wondering about that. Yeah, that’s a good idea. They won’t know what to make of it while I think up something to write.

Valid September 9th, 5 PM AST. I think you should really consider this today; talk to your friends about it. You might want to go to NOAA and look at all of them, to see how this one gets to this point. I strongly recommend that you do that.

Next, here is some rain data from Pima County. Then, some from the USGS. Dan Saddle, up there on Oracle Ridge looks to have gotten the most in a nearby gauge in the Catalinas, with 0.83 inches measured. Was that really the most that fell up in our mountains yesterday. Of course not! Not enough gauges to hit all the cores that struck those mountains, and its without doubt than 1-2 inches fell in the best ones.

2:21 PM. Dancing strands storm joins the fray from the west, dark base about to unload.

In conclusion, Q. E. D.

In spite of the numerous heavy shafts of rain around yesterday, none formed above Catalina, except at the north end of town over there by Edwin Road where they had quite a dump in the middle of the afternoon. Only 0.12 inches here in the Heights of Sutherland. Still it was nice to see those Cumulonimbus blossom into such majestic clouds yesterday. So, today may be it for them, at least close to us. Here are a few more sights from yesterday’s fine day:

6:06 AM. Day started with some fine-looking Altocumulus castellanus, which, according to my cloud chart, one that can be found in fine school catalogs everywhere, it might rain within 6-96 hours. Worked out pretty well yesterday.

9:34 AM. Of course, the best indicator of a good Cumulonimbus day ahead is tall spindly clouds like these. Shows the atmosphere is loaded with instability, or, if you really want to get fancy, CAPE (Convective Availiable Potential Energy). Clouds are going to mushroom up very easily, and way past the ice-forming level where rain will form.

10:32 AM. And within the hour, rain was falling beyond the C-Gap.

11:34 AM. A siting of the seldom seen "pileus" cap cloud on top of a rapidly rising turret. They were all over the place yesterday, but are "seldom seen" since they last only a few seconds as the turrets punch through them. — 11:34 AM. A siting of the seldom seen “pileus” cap cloud on top of a rapidly rising turret. They were all over the place yesterday, but are “seldom seen” since they last only a few seconds as the turrets punch through them.

12:18 PM. This pretty sight of Cumulus congestus with a remnant of a thin tower that had shot up and glaciated.

12:34 PM. Within a few minutes, those two congestus clouds had erupted into this beauty toward the north end of town. — 12:34 PM. Within a few minutes, those two congestus clouds had erupted into this beauty with another pileus cap toward the north end of town.

OK, that’s it. The End.

Last chance for August rain?

An unusually strong “trough” (a bend in the winds that points to the Equator) aloft will be moving across our region today, and as it does, it will be clustering storms, much like they were bunched together two days ago. Remember that those bunched thunderheads came through in a band about mid-day. Something similar is foretold for today, except a little later. We hope that it takes a little longer than about 25 minutes to go through today, too. Violent weather is expected in AZ today, too, with the PHX NWS office particularly worked up by this possibility and that office has already issued public advisories about frequent lightning, terrific winds, and huge dumps of rain.

Dry and fall like days will follow today…..meaning morning low temperatures will probably drop into the 60s here as the dry invading air moves over us. With the lower sun angle these days leading to deeper blue skies overhead, the lower morning temperatures, you will definitely be thinking about college fubball in the days ahead.

Pay especial attention to what Bob has to say, our premier senior heavy weather forecaster, and your NWS for watches and warnings. Mike at the U of AZ will be weighing in as well later this morning. Could it be a tube day, too, somewhere? Will be watching.

Not very certain there will be any more August rain here after this, a very dark thought. As you know the chances of rain start to decline at this time of year.

Catalina summer rain frequency chart — Looks like it needs to be updated…..

Yesterday’s clouds (not in chronological order, just because…)

Maybe I make it too easy for you every day…

Ice developed early and often in those morning Cumulus as they transitioned to weak Cumulonimbus clouds with tops that weren’t so high, but considering how early that happened, it led someone to think that it might be a really good thunderstorm day. But then the air aloft dried out and those Cumulus tops couldn’t reach the ice-forming level by afternoon, which was quite a disappointment for someone.

Here are some pretty cloud scenes for you:

11:01 AM. Ice is obvious here. But, what kind of ice? If you look closely you can see that the ice crystals in this glaciated turret are comprised of hollow sheaths and needles, since the top of this cloud modest; not that high and cold. Well, that’s what I thought, anyway, just something about the texture…. Those kinds of crystals form at temperatures higher than -10 C (14 F), which is an unusual occurrence in Arizona. Happened yesterday because cloud bases were warm to start the day (about 10 C, or 50 F). Huh? Seems like a non-sequitur. “Strangely believe it”, as we like to say here, ice forms at higher temperatures as the bases of the clouds get warmer because ice formation is tied to drop sizes. The warmer the bases, the larger the drops reaching the freezing level in Cumulus turrets, and those larger drops freeze at higher the temperatures.

6:27 PM. A parheila or sun dog, or mock sun in Altostratus cumulonimbogentius (of course). Caused by ice crystals falling flat on their face, hexagonal plates, pristine ones, without any riming (cloud drops that have bumped into them and froze)

7:02 PM. Evening Cumulonimbus with a nice rain shaft; sent a few bolts “down” which is technically incorrect since the most luminous thing you see is called the “return stroke” and actually is going from the earth to the cloud.)

11:01 AM. Small Cumulonimbus forms over the Catalina Mountains. The turret on the left side is still mostly water, but would have a lot of small ice crystals in it. The center of the photo turret has glaciated, few or no liquid droplets exist.

6:26 PM. Cumulus highlighted by the setting sun under Altostratus or Cirrostratus (take your choice–Cs can have shading late in the day, otherwise, no shading for Cs. So pretty a scene.

Just a nice closeup of a Cumulus turret. The variation in shading displays the complicated arrangement of liquid water content in the cloud, those darker areas having more.

9:43 AM. Going up? The Cumulus began forming on the Catalinas about 9 AM, a pretty early start, and that, a good sign of Cumulonimbi in our future.

DSC_0203-1 — 5:24 PM. Just another just a pretty scene with Cumulus humilis and congestus.

The End.

Cbs off early and often yesterday

Day went pretty much as planned for us by the models, with Cumulonimbus (“Cbs”, in texting form) clouds arising early and often, moving in from the SW, more of a fall pattern (which is approaching too fast for this Cb-manic person). If anything, those clouds arose earlier than expected with dramatic morning results;

But those storms that got here divided as they approached The Heights yesterday; cell cores went right and left with places like Black Horse Ranch down by Golder Drive getting 0.53 inches, and a place in Saddlebrooke, 0.94 inches yesterday, while we only received 0.23 inches.

Seeing this happen in real life was tough. Still, there was a last rain burst after only 0.14 had fallen that was really great as the sky began to break open and the sun was almost out when it happened. That last parting shower dropped a final 0.09 inches in just a few minutes. So, maybe we were a little lucky.

BTW, you can get area rainfall from the Pima County ALERT gauges here for the past 24 h. And, also, from the U of AZ rainlog network here. USGS. Coco. NWS climate reports. (Editorial aside: (earlier cuss word, “dammitall”, has been removed)—WHY don’t they gather all the rain reports into one comprehensive site???!!!)

7:04 AM. Soft top Cumulonimbus protrudes high above other clouds producing a long shadow on a lower Altocumulus perlucidus layer.

7:04 AM. Soft-serve Cumulonimbus calvus top emerges above lower Cu and Altocumulus clouds. — 7:04 AM. “Soft-serve” Cumulonimbus calvus top emerges above lower Cu and Altocumulus clouds. This kind of top goes with weaker updrafts, likely less than 10 mph.

10:04 AM. Showers and heavy Cumulus (Cumulus congestus) continued to range along the Catalina Mountains toward Oracle. These were nice clouds.

10:14 AM. Looking in the upwind direction from Catalina, not much going on though storms are raging in the Catalina Mountains. That farthest line of bases, though, drew your attention yesterday, I am sure, given the explosive conditions we had for storms. — 10:14 AM. Looking in the upwind direction from Catalina, not much going on though storms are raging in the Catalina Mountains. That farthest line of bases, with that fat one out there toward I-10, though, drew your attention yesterday, I am sure, given the explosive conditions we had for storms.

10:36 AM. OK, this is looking potent. Finally, tops have reached the ice-forming level and precip is ejecting out. — 10:36 AM. OK, this is looking potent. Finally, tops have reached the ice-forming level and precip is beginning to eject out the bottom of the one on the right. So big, high, top visible, which was of concern, thinking it might only be a light rainshower. Generally, the higher the tops, the more that falls out the bottom¹.

10:57 AM. A two part panorama of the incoming, broken line of storms. Part A above, looking SSW with Pusch Ridge on the far left.

10:57 AM. Part B of panorama, looking at this exciting line of showers and thunderstorms toward Twin Peaks, Marana, and Oro Vall

11:07 AM. A strong shaft has developed, indicating much higher tops than in the earlier scene above at 10:57 AM.

11:14 AM. Hole in rain aiming for house! Will cloud roll, buoyed my outflowing winds ahead of rainy areas develop new rain shafts? — 11:14 AM. Hole in rain aiming for house! This could be bad! Will cloud roll ahead of rain areas, buoyed my outflowing winds ahead of them develop new rain shafts?

12:23 PM. By this time it was all over, the 0.23 inches had fallen, leaving some evidence of flooding. In a change of pace, I wanted to get that evidence in combined with a sky photo so that you could see that there were still clouds around. Cloud has some ice in it, too.

3:53 PM. A final threat of rain appeared as the winds turned briskly from the north and new turrets formed above it and, for a time, headed toward Catalina. It was a dramatic scene, to be sure, but one that disappointed. The clouds forming about the outrushing wind from heavy rain to the north, diminished in size as they approached, no longer reaching high enough to form precip. Partly this is because of our lower temperatures yesterday afternoon, and because when the air goes southbound from areas to the north, its always moving a little downhill and that works against new clouds, too.

3:59 PM. While the dissipation of those clouds was disappointing and not unexpected, to be honest, still it was good to be out and see how green the desert has gotten since the end of July. — 3:59 PM. While the dissipation of those clouds to the north was disappointing and not unexpected, to be honest, still it was good to be out and see how green the desert has gotten since the end of July.

The End

Oops today is supposed to be drier witih isolated Cbs, more tomorrow as moisture from TS Lowell leaks into AZ.

The extremely strong hurricane that forms after TS Lowell is sometimes, in the mods, seen to go into southern or central Cal (!) as a weak remnant circulation or stay well offshore, as in the latest 11 PM AST run from last night.So, lots of uncertainty there. Check out the spaghetti below for the bad news:

Valid in ten days, Aug. 19th, 5 PM AST. Those blue circles WSW of San Diego represent a clustering of the most likely position of that hurricane then. And, that cluster is too far to the west to us, or maybe even southern Cal any “good.”

—————————–Historic footnote——————————
¹“TIme to be distracted from the task at hand…. “Generally”, of course, is a fudge word. For example, in the tropics, it was learned back in the 1960s that rain fell as hard as it could about the time the tops reached the freezing level, and before ice had formed. Didn’t rain any harder even if the tops went to 30 or 40 thousand feet! These results were confirmed in aircraft measurements in the Marshall Islands, oh, back in ’99 (Rangno and Hobbs 2005, Quart. J. Roy. Meteor. Soc.).

Some of the biggest rain drops ever measured (5-10 mm in diameter!) were in clouds in the Hawaiian Islands whose tops that had not reached the freezing level–see Bob Rauber’s 1992 paper in J. Atmos. Sci., with Ken Beard, the latter who tried to get rid of intercollegiate athletics at UCLA when he was there in the turbulent late ’60s, as did the present writer at San Jose State (a story for another day). But then, BOTH me and Ken went on to become science weathermen, not the radical kind of Weatherman, i. e., those under Bernadine and Bill, because we left our radical roots and reggae back behind in the ‘1960s, 70s, and/or 80s (well, maybe not reggae…)

Yesterday’s clouds2

The End

Yesterday’s clouds

Yesterday’s clouds

The End!

The weather ahead….

The weather WAY ahead

Yesterday’s clouds, if you care

Yesterday’s clouds

The weather way ahead

Yesterday’s clouds (not in chronological order, just because…)

The End.

The End

Yesterday’s clouds²